How to prevent S Cracks

S cracking can occur on pieces that dry unevenly, for instance if you take a bowl and put it in front of a fan. Other reasons for S cracks are leaving water in the bottom of your piece during the drying out phase. To reduce the risk of S cracking:

Make sure to compress the piece.

Do not leave water at the bottom of the piece before putting it away for the drying process.

Tap the center of the underside of the piece that is still in the leather-hard stage with your finger. It may seem that the ever so slight indentation your finger produces is enough to eliminate the S-shaped crack that appears in the drying stage or during the firing process. This simple, but very effective technique, should also work on hand-build flat bottom items.